Field of the Invention
The present invention relates to a thermostatic mixing valve for mixing cold water and hot water and to setting the mixed water temperature.
Description of the Background Art
The structure and operating mode of such a thermostatic mixing valve is disclosed, for example, in DE 10 2006 032 018 A1, according to which the thermostatic mixing valve for setting the mixing water temperature can be built into a sanitary fitting, for instance, into a shower.
DE 10 2008 058 515 A1 discloses a generic thermostatic mixing valve, in which the setting of the mixed water temperature is no longer preset manually via an operating knob by the user, but rather the thermostatic mixing valve can be controlled remotely by the user. To this end, the thermostatic mixing valve has an electric motor that acts via a gear stage on a stroke-adjustable valve body with which the size of hot water and cold water control openings can be varied over a setting range, namely, depending on a target mixed water temperature value set by the user.
In DE 10 2008 058 515 A1, the electric motor is assigned a sensor element for detecting at least one set position of the thermostatic mixing valve. The sensor element is a switch that operates together with a cam ring rotationally coupled to the electric motor. The cam ring has two cams of different sizes by which the setting range of the thermostatic mixing valve can be established and/or a calibration set position can be detected for calibrating the mixing valve.
For a reliable detection of the setting range of the mixing valve, it is provided in DE 10 2008 058 515 A1 that the electric motor rotational angle traversed during the setting process is designed much smaller than one rotation, i.e., smaller than 360°. However, this greatly reduces the available setting range for the thermostatic mixing valve. In addition, the arrangement of the switch and the cam ring in the thermostatic mixing valve is intensive in terms of both space and parts.
In DE 10 2008 058 515 A1 the drive spindle of the electric motor is furthermore coupled rotationally fixed via a spline to an adjusting nut, designed space-intensively and approximately cup-shaped in cross section. The cup-shaped adjusting nut has an inner thread that works together with an outer thread of the overload unit. In a setting process, the adjusting nut is caused to rotate, resulting in a corresponding stroke movement of the overload unit.